Power transmission belt



April 11, 1944. H. c. scHAPl-:R

I POWER TRANSMISSION BELT Filed March 5l, 1942 Patented Apr. 11, 1944 y UNITE D STATES PATE NT F Fl C E 2,346,510 l l POWER` .TRANSMISSION BELT 'Harry C; Schaper, Buffalo, N. Y. Application-March 31, 1942,.seria1 No. .436,080

S'Claims.

'My invention relates to power transmission ybelts :generally known as V-ibelts.

The accepted and conventional types Yof V- beltsof present day constructon are.` made :by a process of molding rubber or other flexible .substance or compound in which cords or fabric .plies are embedded in order to increase the tensile strength of .the belt. Such belts are ordinarily made endless in various pre-determined lengths, each length requiring a separate mold, Which procedure .results in high costs of manufacture. Because of the materials used and the method of manufacturabelts produced from the same `mold often have a variance in length and thus for multiple-drive belts extreme care must be exercised in selecting belts of identical lengths so 'as to provide uniform loading `of the individual-belt 'members for the particular work for whichY they are designed.

The tendency of vbelts of this construction 4to' the belt and renders the same unfit for service.`

Furthermore, when slippage occurs the angular Working surfaces of' such' molded belts become glazed, thereby reducingthe lcoeflicient Vof friction with a proportionate loss 'of 'transmitted power.

To obtain a higher coelcient of friction, sev-` eral types of V-belts are manufactured in which leather is used, one type having a solid continuous V section. Another 'type has a series of spaced solid cog rsections Vformed integral with or fixed to a continuous band located on the upper surfaces of the cogs. v

It is obvious that in the solid continuous type, flexibility is reduced to a point Where exceedingly large diameter sheaves are required to assure satisfactory contact of belt with the grooves in the sheave so that aside from the gain in coefficient of friction, the cost of the large sheaves prohibits the general use of belts of` this type.

Thespaced sectional type of leather belt `provides greater flexibility, thereby permitting the use of 4,smaller diameter sheaves, but the application of. leather as described has a characteristic .tendency to contract :and expand` under Vvarying -climatic and temperature conditions, thereby causing variable tension in the belt with a result'- ant loss of power when expanded and excessive bearing pressure when contracted.

Because of the aforesaid disadvantages attending the construction and use of leather cornposed belts, although admittedly of a higher coeicient of friction, such belts have not been generally accepted by power users. v

The principal object of `my invention is, `to generally improve upon and lsimplifythe construction of the existing forms of V-belts and to provide a simple, practical construction which may be manufactured with economic advantage and which eliminates the disadvantages herein pointed' out in connection with V-belts as now .manufactured and used. v

1A further objectof my invention is, to provide a fabricated V-belt, the working surfaces `of which may be made of alreadily obtainable, in-

expensive material such as scrap leather.

A further object of my invention is, to provide a V-belt that includes a non-stretching, length determining, power transmitting member, which enables an accurate preedetermined length of V-belt to be produced.

Further objects of my invention are, to provide a V-belt structure including a plurality ofsets of friction elements adapted to engage inthe grooves of a multiple groove sheave, thus providing a multiple V-belt which functions in .the transmission of power as a single belt, further, `to provide a V-belt in which a maximum of coefficient of friction is combined with a minimum of internal frictional heat development, and further,`1 to provide abelt of the character referred tofWhich may be manufactured in roll lengths and be-readily reduced to usable lengths as required and 'such belt capable of being easily assembled and installed. i

With the foregoing and other objects in View, my invention consists in certain novel features of constructionand arrangement of parts that will be' hereinafter more fully described and claimed and illustrated in the accompanying drawing in which:

Fig. 1 is a side elevational view of a V-belt constructed in accordance with my invention, the same being shown inoperative position on a pair of'sheaves and with parts of one sheave broken awayand in section.y

Fig. 2 is an enlarged lcross sectional view ltaken on the line 2--2 of Fig. 1. N Fig 3` issafragrnentary -plan viewshotving` a portion of the endless power transmitting member with friction elements attached thereto.

Fig. 4 is an elevational sectional view taken on the line 4--4 of Fig. 3.

Fig. 5 is an elevational view with parts in section and showing the laminated friction elements in the positions occupied while in the groove of a sheave.

Fig. 6 is a plan view of a portion of a belt constructed in accordance with my invention and which includes a plurality of sets of friction elements arranged on the endless member so as to provide a multiple V-belt.

Fig. 7 is a side elevational view of the multiple V-belt and showing the connection between the ends of the endless power transmitting element.

Fig. 8 is an enlarged cross section taken on the line 8-8 of Fig. 6 and showing a portion of the sheave that carries the multiple V-belt. I,

Referring by numerals to the accompanying drawing which illustrates a preferred embodi-` ment of my invention, IE! designates the power transmitting member which is preferably constructed from a single piece of thin, exible metal such as steel of high tensilestrength and the ends thereof being permanently connected in any suitable manner, preferably by rivets,V I I.

Mounted on the inner face of memberv I0 is a row of laminated friction elements which are spaced apart lengthwise of Asaid member with the layers or laminations I2 disposed longitudinally of member Il] and secured to the latter at one end by suitable means, preferably a rivet or rivets I3. These laminations I2 are preferably'formed of flexible material such as leather, rubber, rubber composition, or rubber impregnated fabric, and as each set of laminations is secured to member I0 at one end only., in cantilever fashion, the greater portions of the bodies of the laminations are free to flex toward and away from member I0 as the belt passes around and between the sheaves upon which itv is mounted.

Thus the laminations of the friction elements are free to assume various curvatures so as to conform with the diierent diameters of the grooves G in the sheaves S upon which the belt operates.

The width of the individual laminations I2 gradually decreases away from the member I 0 and the sides of said elements are provided with correspondingly inclined faces I4 so as to conform to the angularity of the sides of the grooves in the sheaves and said angular faces providing the frictional surfaces of the belt.

Thus frictional contact is provided by the edge surfaces of the laminations and it is well known that the coefficient of friction is greater, on the edge surfaces than on the flat surfaces of leather and thus a belt of my improved construction provides a maximum of coefficient of friction.

The pressure contact of the laminated yfriction elements when engaged with'the surfaces of the grooves in the sheaves S causes the free ends of the laminations to be flexed into distorted circular lines after breaking `Contact with lthe groove in the sheave as illustrated in Figs. 1 and 4, thus causing the free ends of thelaminations to separate when traveling between the sheaves and which separation results in an effective dissipation of internalfrictional heat.'

In power transmission drives now in general use and which include multiple groove sheaves and V-belts, a number 'of individualv belts are used. When one or more of the belts break as a result of unequal tension, it is necessary to replace the entire set of belts for the reason that continual use of belts causes the same to stretch and thus a new belt would not match those belts remaining in the old structure.

In Figs. 6, "I, and 8, I have illustrated a multiple V-belt which comprises a single power transmitting member I0a. similar to member I0, but obviously wider, and which carries on its inner face a plurality of longitudinally disposed parallel rows of laminated friction elements, said rows being spaced laterally so as to engage the grooves G in a multiple sheave M, thus providing ample frictional contact in multiple form but acting as a single unit.

While I prefer to use fiat, resilient metal, preferably steel, for the power transmitting member when used as a single belt, it may be desirable in the construction of a multiple belt to use a flat belt having great flexibility combined with high vtensile strength for the reason that the power transmitting member when used in connection with multiple drives has width sufficient to furnish the necessary power without sacrificing exibility,

In the multiple type belt illustrated in Figs. 6, 7, and 8, the ends of the member Illa are united by resilient plates I5 that are applied to the outer face of the member Illa and arranged so as to bridge the joint between the ends and said plates being secured to member Illa by the same rivets IB that are used in attaching the laminated friction elements to the power transmitting member adjacent the joint therein.

. I prefer to construct the power transmitting elements I0 and Illa slightly narrower in width than the width of the laminated friction producing elements in both the single and multiple construction as illustrated in Figs. 2, 6, and 8, thus eliminating any frictional contact between the side edges of the power transmitting member and the flanges of the sheaves.

It is to be noted that in my improved belt, the groups lof laminated friction elements are spaced apart longitudinally of the continuous member Ill, and as the laminations forming said elements are connected to each other and to said member at one end only, all of the laminations of each group are free to flex independently during travel and particularly while passing onto and from the sheaves.

Thus it will be seen that I have provided a power transmission belt that is relatively simple in construction, inexpensive of manufacture and very effective in performing the functions for which it is intended. i

It will be understood that minor changes in the size, form and construction of the various parts of my improved power transmission belt, may be made and substituted for those herein shown and described, without departing from the spirit of kmy invention, the scope of which is set forth in the appended claims, i

I claim as my invention:

1. In a V-belt, a continuous iiexiblepower transmitting member and a plurality of laminated friction elements secured at one end only to the inner face of said power transmitting member and spaced apart longitudinally thereof.

2. In a V-belt, a continuous flexible -power transmitting member, a plurality of longitudinally disposed laminated friction elements secured at one endy only to the inner face of said power transmitting/member and spaced -apart longitudinally thereof and which laminated friction elements are provided with inclined side faces.

3. In a V-belt, a continuous flexible power transmitting member, a plurality of longitudinally disposed laminated friction elements carried by the inner face of said power transmitting member and spaced apart longitudinally thereof and each set of laminated friction elements being secured to the power transmitting member at one end in cantilever form.

4. In a power transmission belt for sheaves having a plurality of spaced grooves, a continuous exible power transmitting member and a plurality of laminated friction elements secured to the inner face of said power transmitting member and spaced laterally and longitudinally thereof so as to engage in the grooves of said sheaves said power transmitting member having no frictional contact with said sheaves and being connected to said flexible member at one end only.

5. In a power transmission belt for sheaves having a plurality of spaced grooves, a continuous flexible power transmitting member, a plurality of laminated friction elements secured to the inner face of said power transmitting member and spaced laterally and longitudinally thereof so as to engage in the grooves of said sheaves and each laminated friction element being secured to said power transmitting member at one end in cantilever form said power transmitting member having no frictional contact with said sheaves.

6. In a power transmission belt for sheaves having a plurality of spaced grooves, a continuous exible power transmitting member, a plurality of laminated friction elements secured at one end only to the inner face of said power transmitting member and spaced laterally and longitudinally thereof so as to engage in the grooves of said sheaves and the laminations of which frictional elements are iiexible said power transmitting member having no frictional contact with said sheaves.

7. In a V-belt the combination with a continuous flexible power transmitting member, of a series of longitudinally disposed exible laminated friction elements secured at one end only on the inner face of said power transmitting member and spaced apart longitudinally thereof.

8. In a V-belt the combination with a continuous flexible power transmitting member, of a series of exible laminated friction elements arranged on the inner face of said power transmitting member and spaced apart longitudinally thereof and each laminated friction element being secured at one end only to said power transmitting member.

HARRY C. SCHAPER. 

